Lighting and other gear for an event, e.g., a concert, play or other gathering may be held on trusses. For example, a truss may include a series of poles which extend substantially parallel to one another and, are connected together to form a square or rectangle in cross section. Cross pieces on the truss that hold the pieces relative to one another and provide structural support.
The trusses need to have significant amounts of strength, and hence they use materials that can be heavy. Also the trusses are usually raised to a spot above the stage. Often the stage is assembled by wheeling out the trusses on dollies. The lights are hung on the trusses on the ground while they are still on the dollies. The trusses are subsequently raised so that they are hanging from the roof with the lights still on them. The dollies are then removed from that area and stored until the trusses are lowered.
Dollies for trusses include the “Obie Low Pro” and the “Mega Truss dolly”.